The profiling of a blank, for example in the form of a pot-shaped blank, into a work piece is accomplished by holding the blank on an arbor or support having a profile along its outer surface corresponding to the tongues and grooves to be formed in the wall of the blank. The profile of the support or holding arbor cooperates with profiling rollers arranged concentrically, whereby the work piece and the profile rollers are movable in parallel to the longitudinal axis of the tool as well as relative to each other. Such an apparatus and a method for the formation of the tongues and grooves is disclosed in German Patent Publication DE-A1 2,829,041 (Mehler et al.) published on Jan. 10, 1980. The blank used conventionally is a sheet metal member, whereby the arbor carrying the blank is pressed through a profiling roller arrangement which rolls along the blank in parallel to the central longitudinal axis of the tool.
The profiling roller arrangement comprises a plurality of profiling roller sets that are arranged concentrically around the central longitudinal axis of the tool. These roller sets can be arranged either next to each other or axially above each other. When the rollers are arranged next to each other a so-called transfer press is used as a drive for the support arbor which carries the blank while simultaneously supporting the profiling roller arrangement. In the second case in which a plurality of concentrically arranged profiling rollers are positioned axially above one another, a simple press with its upper and lower press die sections forms a driving unit.
German Patent Publication DE-OS 2,017,709 (Propach et al.) published on Nov. 4, 1971 discloses a tool for forming longitudinal grooves in a cylindrical work piece, wherein the profiling rollers are mounted for adjustment in the direction of a force exerted by the rollers. Two support rollers contacting one profiling roller at the roller circumference are provided for each profiling roller. The support rollers are rotatably mounted in a bearing block and cannot be displaced. The support rollers take up the forces which are effective on the profiling rollers. Such a structure is intended to relieve the profiling rollers as much as possible from the deformation forces so that the mounting and thus the profile rollers themselves can be dimensioned smaller than would be necessary otherwise.
With the apparatus according to German Patent Publication DE-A1 2,829,041 it is possible to produce the cylindrical work pieces with a radially outwardly and a radially inwardly facing gear teeth configuration and such production can proceed substantially in a fully automatic manner with the required large precision. However, the known apparatus is feasible from an economic point of view only if large production numbers are to be produced.
The use of a method or an apparatus for the above described profiling operation is controlled by the question whether such use is economically feasible so that a certain method or apparatus is used only when the costs per piece produced are advantageous. This requirement could not be met by the apparatus disclosed in the first mentioned German Patent Publication when small production numbers were involved.